TradeTodaysPosition Size Calculator
Position sizing is the single most important risk-management decision in trading: it decides how much money a losing trade will cost you. This calculator converts your account balance, your planned risk percentage and your stop-loss distance into an exact lot size.
The Formula Behind It
Position size (lots) = (Balance × Risk %) ÷ (Stop loss in pips × Pip value per lot)- •Balance — the money in your trading account.
- •Risk % — the share of the account you are willing to lose on this trade (for example 1%).
- •Stop loss in pips — the distance between your entry and your stop-loss order.
- •Pip value per lot — contract size × pip size, converted into your account currency (e.g. $10 per standard lot on EUR/USD for a USD account).
How to Use This Calculator
- 1
Decide your risk percentage before you look at any trade setup. Many traders use 1–2% as a guideline.
- 2
Identify where your stop loss must sit (swing low/high, structure level) and measure that distance in pips.
- 3
Select the currency pair and your account currency. The pip value is calculated automatically.
- 4
Enter your values and read the position size in lots.
- 5
Round the result down to the nearest step your broker allows (usually 0.01 lots) and place the stop loss exactly where you planned.
Worked Example
You have a $10,000 account, you risk 1% ($100) per trade, and your EUR/USD setup needs a 25-pip stop loss.
Pip value for 1 standard lot of EUR/USD in a USD account is $10. Position size = $100 ÷ (25 pips × $10) = $100 ÷ $250.
Result: 0.40 lots. If the stop loss is hit, you lose about $100 — exactly 1% of the account.
Important Risk Note
This calculator uses standard contract sizes and assumes your stop loss executes exactly at its level. Slippage, gaps and weekend moves can make real losses larger than planned. Leverage does not change position size, but it does change your margin usage — check the margin calculator before opening a trade. Educational use only.